Meta publishes a width range of 320 px to 1440 px for Threads images and an 8 MB cap rather than one recommended size. What catches people is the crop, since anything taller than 4:5 on the Threads placement is cropped and vertically centered to 4:5.
Where it shows
- The Threads home feed, inside the post column
- The post grid on your Threads profile
- The full screen image view when someone taps a post
- Post previews inside replies and quotes
The safe zone
The post column tops out at 1440 px wide, and a taller than 4:5 image is trimmed from the top and the bottom to fit, so those two bands are the ones at risk in a tall graphic. Keep the subject and any type inside a 4:5 window drawn in the middle of the frame. Threads also converts anything that is not sRGB, so a wide gamut export shifts in color before a single person sees it.
Quirks worth knowing
- Meta publishes a width range of 320 px to 1440 px, scaling up anything narrower and down anything wider, so there is no single recommended pixel size to quote.
- The API accepts an aspect ratio up to 10:1, which means a very tall or very wide file uploads without an error and only looks wrong once it is live.
- The crop rule is published in Meta's Threads ads spec rather than in the organic documentation, stating that images taller than 4:5 are cropped and vertically centered to 4:5, and that is where the ratio in this record comes from.
- Images are converted to sRGB on the way in, so a Display P3 export arrives less saturated than it left your editor.
- Only JPEG and PNG are named as officially supported for image posts, so a HEIC straight off a phone is not covered by the documentation.
- The 8 MB per image cap is tight for a 1440 px wide photo exported at maximum quality.
Common mistakes
- Reusing a 1080 x 1920 px Story graphic, which is far taller than 4:5 and loses a band from each end.
- Exporting at 2048 px wide for sharpness, which Threads scales back down to 1440 px anyway.
- Sharing straight from the camera roll and assuming every format is handled.
- Putting the punchline at the bottom of a tall graphic, the first strip the 4:5 crop takes.
What we recommend
- Lay the design out inside a 4:5 window so nothing that matters sits where the crop lands.
- Export at 1440 px wide, the widest size Threads keeps, and stay under the 8 MB cap.
- Convert to sRGB before exporting so the colors you signed off are the colors that post.
- Use JPEG for photographs and PNG for flat graphics with type, the two formats Meta names.
Common questions
What size should a Threads image be?
Meta publishes a range rather than a fixed size, from 320 px to 1440 px wide, scaling anything outside it to fit. 1440 px wide is the practical target because it is the widest Threads keeps without downscaling. Keep each file under the 8 MB limit.
Why did Threads crop my image?
On the Threads placement, images taller than a 4:5 ratio are cropped and vertically centered to 4:5. A 9:16 Story graphic loses a band from the top and another from the bottom. Rebuild the layout inside a 4:5 frame and the crop stops mattering.
What image formats does Threads support?
JPEG and PNG are the officially supported types for image posts, and everything is converted to sRGB on upload. Other formats may go through the app but are not documented. Exporting deliberately is safer than sharing from a photo library.
Can I post the same image to Instagram and Threads?
Usually yes, because a 4:5 Instagram portrait post fits the ratio Threads keeps without any cropping. A 9:16 Story or Reel cover does not, and gets trimmed at both ends. The other thing to check is the 8 MB per image cap on Threads.
More answers on thumbnail, carousel and cover questions are on the FAQ.